Can tester



July 6, 1937. w. E. BURNS 2,086,116

CAN TESTER 47 INVENTOR MFG/eo @we/v6 ATTORNEY July 6, 1937. w. E. BURNS 2,086,116

CAN TESTER Filed Oct. l, 1934 l -SheetS-Shee 2 INVENTOR M//L F020 E BUR/#v5 ATTORNEY W. E. BURNS July 6, 1937.

CAN TESTER Filed 001'... l, 1934 5 Sheets-Sheet 3 July 6, 1 937. w. E. BURNS CAN TESTER Filed Oct. l, 1934 5 Sheets-Sheet 5 R O T N E V .N.

Patented July 6, 1937 CAN TESTER Wilford E. Burns, Burlingame, Calif., assigner to M. J. B. Co.

Application October 1,

4 Claims.

rlhis invention relates to improvements in can testing devices, and it has reference more particularly to machines of that character whereby tin cans are tested for leaks prior to their being lled; it being the principal object of the inventionto provide a machine whereby cans, each with one end thereof permanently closed, may be tested with accuracy and rapidity and whereby the p-resence in a can of a defect that would permit an undesirable or detrimental leak may be detected.

Generally stated, the pres-ent invention resides in the provision of a testing mechanism oi the above stated character comprising a plurality of testing chambers wherein the cans are individually disposed and sealed for purpose of making a test thereof; the chambers being slightly larg-er than the cans and adapted to seal the cans therein in a manner whereby the volume inside each can is sealed from the volume of the enclosing chamber that surrounds the can. Also, means is provided for applying air under pressure to the interior of the cans when so Sealed and other means is provided to visibly indicate the building up of any air pressure in the chamber enclosure at the outside of the can that would result from leakage of air thereintc from the inside of the can by reason of any defect on the can wall such as a pin hole leak or defective seam.

More specifically stated, the objects of the present invention resid-e in the provision of a testing machine of the above stated character, comprising a horizontal table that is revoluble about a central aXis and on which table, at established intervals are means for accurately locating the cans in position for testing, and wherein testing bells are supported above the table and in alinement with each of the said locating means and are each reciprocally movable toward and from the table, first to enclose seal a can therein for testing, then, after a predetermined interval during which the testing operation is effected, to uncover the tested can for its removal from the machine.

It is also an object of this invention to provide means whereby the movement of a bell to a position for enclosing a can, not only seals the chamber but also seals the can, thus to provide separate sealed compartments inside and outside of the can.

Another object of the invention is to provide novel valve mechanisms, operable automatically incident to rotation of the table, to effect an application of air under pressure to the cans after 1934, Serial No. 746,292

being sealed in the bell chambers and to provide for relief of air from the chambers surrounding the cans during the periods of application oi air pressure to the inside, then, after the periods of ination of the cans by reason of application of 5 air pressure thereto, to seal the outer chambers against escape of pressure to atmosphere and subsequently to open a channel from the outer chambers to a bubble test instrument Yto indicate whetheror not a pressure had been built up by leakage from the inside to the chamber outside the can.

Still other objects reside in the provision of means whereby movements of the testing bells between raised and lowered positions for sealing the cans, are automatically effected in timing with and incident to rotatable advance movements of the table.

Other objects of the invention reside in the details of construction and combination of the various parts and in their mode of operation, as will hereinafter be fully described.

In accomplishing these and other objects of the invention, I have provided the improved details of construction, the preferred forms il?vr of which are illustrated in the accompanying drawings, wherein- Fig. 1 is a sectional View of the testing machine as seen in a vertical plane through the axis of the machine and illustrating one of the testing bells in raised position.

Fig. 2 is a sectional detail, Von line 2 2 in Fig. 3, illustrating the means provided for making certain adjustments to accommodate cans of different height.

Fig. 3 is a horizontal section of the machine, taken on line 3 3 in Fig. 1. Y

Fig. Il is a horizontal section on line 4-4 inf Fig. 1. i

Fig. 5 is a plan view of the turret driving ,gearing with some parts in horizontal section.

Fig. 6 is a plan view of the clutch and brake mechanism.

Fig. 7 is a cross section through the clutch device, as seen on line 'l--l inFigs. 5 or 6.

Fig. 11 is a cross sectional detail of the valve mechanism for applying air to the cylinders to raise and lower the testing bells.

Fig. 12 is a cross sectional detail of the valve for releasing air pressure to the bubble testing device.'

Figs. 13 and 13a., respectively, show in top plan View, the rotating and stationary members of the valve for controlling application of the testing air to the cans.

Figs. 14 and 14a, respectively, are the rotating and stationary members of the valve mechanism whereby air is administered to the cylinders for actuating the piston to move the testing bells.

Figs. 15 and 15a, respectively, are the rotating and stationary members of the valve device whereby connection is made between the testing bells and bubble test device.

VReferring more in detail to the drawings:-

I designates the horizontally disposed, circular, testing table and 2 is a vertically extending, tubular shaft which supports and rotates the table. The tubular shaft, as seen in. Fig. 1, is revoluble in bearings 3 and ll formed integral with the spaced upper and lower Walls 5 and t of a housing in which gearing, presently described, is contained for intermittently rotatingthe table. A ball bearing assembly 'I is interposed between the upper end of the bearing 3 and hub of table I to carry the weight of the table I and of the mechanism located thereon.

Located upon the table, concentrieally thereof, is a tubular post 8 having a base flange 9 through which bolts I are extend-ed into the table to fix it rigidly in place thereon. The table I also Vhas an upwardly formed hub portion Ia that is enclosed in the lower end of the post and to which` hub portion the shaft 2 is xed against rotation therein by a key Il.

The upper end of the post 8 is closed by a hori- Zontal wall I2 and this has a central opening I3 in which the upper end of shaft 2 terminates to add strength and rigidity to the table support.

When the machine is in operation, the table I is rotated by intermittent, rotative movements each of which, for the present construction, ad-

' driving the shaft.

varices the table an interval of sixty degrees. This definite movement is by reason of the fact that the table has six equally spaced testing stations thereon.

The driving gearing for the machine is best shown in Figs. 1, 5, 6, and 7, wherein I5 designates a horizontal, driving shaft revoluble in supporting bearings It and I? fixed to or formed as a part of a bracket i8 at one end of the gear housing. This shaft is equipped with a pulley wheel I9 over which a belt may be extended for The pulley wheel may run free on the shaft when the machine is out of gear and it is Idesigned to be operatively connected to drive the shaft and operate the machine through the mediacy of-a clutch mechanism 2li, presently described in detail. The machine is operated under control of a hand lever 2| which is disposed horizontally above the gear housing and is pivotally supported thereon by a pivot bolt 22 extended through the lever at a point between its ends. The lever is operatively connected by a rod 23 with a crankarrn 2li fixed to the upper end of a vertical shaft. 25 revoluble in a supporting bearing 2l that is'bolted to the bracket I8 as seen in Fig. 6. The shaft 25 has a clutch release nger 28 fixed thereto for releasing Vthe clutch, as presently described, and a coiled spring 29 surrounds a part of the rod 23 l and is held under compression between an abutment'il on the rod. and a rod guide 3l fixed to the gear housing. This spring, held under compression, operates normally to hold the lever at a position whereby the clutch is released, however, by rnanual movement of the lever 2i from the full line position to the dotted line position as seen in Fig. 6, the shaft 25 will be rotated in a manner whereby to move the clutch nger 23 to release the vclutch for driving the machine.

The construction of the clutch is shown in Figs. 5 and 'l wherein 33 designates a circular collar that is keyed on shaft I5 and is provided at one side Vwith a recess 3S in which a flat pawl 35 is pivotally mounted. A coiled spring 3S is located in` a bore 3l to press outwardly on a slide 38 which, in turn, bears against the pawl 35 to urge it outwardly as from the full line to the dotted line position shown in Fig. '7. The pulley wheel IB is keyed on a sleeve Ll@ that revolves on shaft I5. At one end the sleeve mounts a collar li that encloses andrrevolves on the collar 33. The collar lI, as seen in Fig. 7, has notches vi2 in its inner surface adapted to receive the outer end of the pawl to effect a driving connection bef IThe pawl is of l position adjacent the collar 33 and. has an arc-V Y uate portion 28a that may be caused to engage the pawl and displace it from driving connection with collar 4I. When the trip nnger 2B is actuated to the dotted line position of Fig. 6, it releases: the pawl and the driving connection may then be established by reason of spring 36 pushing theV pawl outwardly for seating in a notch lt2 ofthe driving collar el.

On the inner end of shaft i5 is a bevel gear pinion i5 in driving mesh with a bevel gear 45 keyed on a vertical shaft il revoluble in bearings 48 and 43 in the top and bottom walls of the gear housing. Keyed on the shaft 'all' below gear 46 is a pinion 5i! meshing with and driving a larger gear 5i keyed on a vertical-shaft 52 revoluble in bearings 53 and 5&1 in the upper and lower` walls of the gear housing.

Keyed on the tubular shaft 2 within the gear housing is a `Geneva gear 55 with which a stud 56 on an arm 55a and segment 5l keyed on theV shaft 52 co-act to rotatably advance the shaft 2 and table I an interval of sixty degrees for each rotation of shaft 52.

In the intended operation, the operator starts the machine by moving the hand lever 2l to the releasing position, as in dotted lines in Fig. 6. This removes the finger 28a from the pawl 35 and permits the pawl to engage the clutch to drive the machine which is automatically stopped after the table has advanced one-sixth of a revolution as will now be described.

By reference to Figs. 1 and 6, it is observed that a circular cam Bil is xed on the upper end of shaft 52 and this is provided at one side with a semi-circular, peripheral recess Gl adapted toseat thereinV a roller 62 mounted on the inner end portion of the starting lever 2l. When the lever 2i is actuated so vas to start the machine, the

roller 62 is'u'nseated from the notch 6I and during the following rotation of the carnit rides upon the periphery of the cam and thus the lever 2l is held in its starting position until the cam 65!) has completed one revolution. Then the roller 62 is againseated in recess ySI under action.

Vpresently described. This base Si Y `:2,086,11e ofthe spring 29. Y The trip nger 28 is simultaneously returned to position to Yengage pawl 35 to release the clutch to stop the driving opera#V tion. Y Y

-Operating in conjunction' with the lclutch is a brake mechanism comprising a brake drurn E55 fixed on the upper end of shaft il and a brake band applied thereto. held by a post @l xed in the -top Wall of the gear housing and its other end is adjustably attached to one endV of a brake lever @Sfthat is pivotally mounted on the housing by a pivot stud 69. This lever has a roller lo at one end in rolling contact with the surface of a cam il formed onthe hub portion of the cam disc The cam 'il is designed to actuate the lever toto eiect a braking action of the band 68 on the drum to Vstop the machine at the end of each rotative action of the table and just as the clutche `is disengaged by the. movement of lever 2i permitted when roller 52 again seats itself within the cam Yrecess The two cams 5&3 and 'il are sorelated that 6l. Y when the brake is appliedv to check the travel of the machine, it will be released just as the roller 62 moves into the seat 6l.

Supported above the table, to revolve therewith justment in accommodating cansl of diierent` height, as presently understood. This frame includes a depending cylindrical hub portion @il that fits telescopically over the post S on the table I. Concentrically mounted von the frame 'l5 is a base 8l for the support of valve devices is :fixed to the frame by bolts Sla, as seen in Fig. l. t Y

Arranged on the frame 'i5 at equally spaced intervals and at equal radial distances from the axis of rotation of the table are air cylinders 82, six in number and vertically disposed. l Each cylinder contains a piston 33 xed on a piston rod 874 that extends slidably through the upper and lower end walls of the cylinders; suitable packing being provided about'the rod as at 82a' to prevent leakage of air pressure from the ends of the cylinders. Attheir lower ends, each of the piston rods is xed to the closed upper end of a testing bell which is adapted to be moved up'- wardly and downwardly in'accordance with the action of thepiston in the cylinder correspond-` ing thereto, thereby to permit the placing of cans in position on the table for testing, and the enclosing of the cans within the bells whenl the latter are actuated downwardly thereover. VThe lower end of each bell is open to permit it to be applied over a can and is provided at the lower end with a peripheral, inset, sealing gasket VBt adapted to be pressed against the table top in an air tight joint. Seated in the upper end of the bell is a rubber base or pad 87 that will be compressed against the open end of the can in an air tight joint when the can is enclosed 'by the bell for testing; thus, as seen in Fig. 9, the bell will be sealed to outside atmosphere and the can will Y also be sealed within the bell.` f It is to be understood that the testing bells 85 -One end of the band is y the 'oa-sei or seat as indicated b-y theopeiin 's will substantially conform in shape to the'cans to be tested and are just slightly greater-in -di-V-V ameter and of approximately the same length as the :cansV so thatwhen they enclose the cans, I there willbe just -a slightV space between the can walls and the chamber vWallsand the air capacityV of the bell outside the can iscomparatively small. The piston rods 84 are tubular to provide for the application of testing air` to the cans'theree through. and the channel te. in each rod comd101V j municates at its lower yend-withv a Vchannel SilaVn leading into thebell through itsupper end Vwall Y and centrally through the rubber pad; Theupf per ends of the piston rods, above the Vpistons',.fV are telescopically containedwithintubular exl5 tensions Se that aremounted on the upper end walls oi' the cylinders 8f3. Flexible pip-c5792;are*v extended from a'distributing valve rjpresentiy Y described,` supported coaxiaily of the machine; j.

tothe upper ends of the extension tubes ed Vto supply vair to the testing bells through thegpisw ton rods, and air tol the 'valve 9,3 isf'supriliedgYy`V througha pipe 913. i.

Application of airto .tie various cylinders l eecting movement ofl the pistons for rai ng and loweringV the testing bells is inadathrough an air supply pipe '95 that extends coaxially within the tubular shaft 2 to a distributing valve supported on the cap Si. Vv'lhis'valve Vmechanism, as disclosed best in Figs. 8, l1,`11i, and lea, comprises a rotating base or seat Si' that is i'ixed upon thecap Shand a stationary valve member S3 which, as seen in Fig. is' ably appliedyto the upper end ofthe air-supp] pipey but cannot rotate thereon. The Iupper g surface of the rotatingV seatY is flat, and 'the vvalve member QS is of disc-like ormfand rests 'flatly Y upon the `rotary member in an airtight joint. A

housing Hill encloses the part @it andf rests upon and is fixed to the b-ase'vl by 4Vbolts itl,

as'sliown in Fig. 8. EachV of the cylirniers liliv pipe connectionsl 62 andVV E63 leadingirom their upper' and lower ends, respectively, to the distributing valve St. The pipes lil are conne'cted with ports it in the rotary base niem-Y ber 9'? and the pipes H32 likewise co'nnecjtrwithports 65. The Yports ltd are equally spaced Y apart about thebase member gland leadradialr ly thereinto, then upwardly to the upperiace ofY 50 idriciy sho-wnV in Fig. ld;A these several oper sf being circularly arranged about lthe Vaxis oro- Y tation of the valve and spaced 6o degreesfapart. The ports it enter the base li angularly'and at points that are intermediate they ports irsiand lead` inwardlyrand then .open upwardly vthrough the face of t-heimernber Si' as designated 'i at .ia in Fig. ill; the arrangement beingsuch that the ports llct and i'iia, which correspondV to the samercylinder 82 open toV the upperv face `60 of lvalve member Q'l in alinementradiaily ofthe j valve,-with the ports S65-a all located in acircle y concentric of the valve and of lesser diameter than the circle of ports mda.

Extended vertically through the valve seat'r 9i V6"5'" at points intermediate radially alined portsY loda? Y valve member v9i lthrough an are of approxi- 715'" mately 310 degrees, as seen in Fig; 14a, and a plurality of ports l open therefrom upwardly through and to the upper face oi the part S8.

A clearance space l 99, asrseen in Fig. 8, is

provided in the housing I6@ above the valve member Q8 and the upper end of air supply pipe terminates in a socketed bushing IIil having ports lll therein opening laterally and downwardly from the socket to the space lil thus to provide for communication oi air pressure from the pipe Sii to ports Hi8. The valve member 98 also has concentrically located grooves H2 and H3 in its under surface directly overlying the circle of ports ia and lo@ respectively. hese grooves extend through an arc coextensive with the groove lill, and they are joined along their opposite end portions for the last thirty degrees as seen in Fig. 14a. There is also a pocket il@ in the under face of the valve member between the] opposite ends of groove H12, spanning an arc oi about 20 degrees and overlying the outer circle of ports llllla'and thereare air ports llt opening therefrom upwardly through the ldisl; 98 to the air chamber Also, there is apoclret H5 in the underv iace oi the disk 98 radially alined with vthe pocket lill and extending across the circle of ports i650. and E36.

For purposes of explanation, the ends oi valve channels iol-l l2 and H3 alined with the radial line S in Fig. 14a, will be designated as the starting ends.

With the valve parts arranged as in Fig. 8, it is apparent that with part 98 stationary and part Sl, as seen in Fig. i4, rotating in a clockwise direction, each set of ports lllla-p-lilt and Etta, will simultaneously pass into registration with the channels H2, H3, and l'i, respectively. Air under pressure supplied by pipe 95 to the valve and applied through the ports M98 to the channel IS? is thereby communicated through the port l and pipe E82 to the upper end of the corresponding cylinder 82 and the piston 83 in the cylinder will be actuated downwardlyto move the correspending testing bell 85 downwardly to enclose and seal a can placed on the table below it in position for testing. As the piston in the cylinder is driven down, air is exhausted from the lower end of the cylinder through pipe IBS, valve port lill, valve grooves H2, H3 and valve ports itt. The bell is thus retained in lowered position while the table rotatably advancesthrough an arc corresponding to the extent of groove lill. When the ports iila and H06 finally pass from registration with the grooves Il `and IIS, they then are brought simultaneously into communication with the pocket H5. At the same time the port dalla will passinto registration withpocket lla and air is supplied through ports ill, Id and pipe 5GB to the lower end of the cylinder S5 to actuate the piston upwardly to raise the bell, and air is exhausted from the upper end of the cyl inder through the pipe loi?, port IE5, pocket IE5 and exhaust ports i535. The arrangement of parts is such that, with respect to the plan of the device as seen in Fig. 3 and with the machine `rotating in the direction of the arrow; the bells 85 are actuated downwardly as they travel along the arc between radial lines 1A and B and they are lifted for removal of the tested can when they reach the radial line C. Testing is done at the station aliried with radial `line D and cans are applied at the station alinedv with radial line E, designated as the operators station.

When a can is placed in position on the table I for testing at station E, it is accurately alined with the axial line of travel of the testing bell which is to enclose it.V When the bell is lowered, it encloses the camas seen in Fig. 9 with the top or open endof the can pressed in an air tight joint against the rubber pad 8l thus to seal the can. At the same time, the bell is sealed at its lower end by contact of the gasket 86 with the table top. Air is then administered to the inside of the sealed can through the tubular piston rodY 8e3 under control' of the previously mentioned valve mechanism 93.

' The valve mechanism 93, as seen in Figs.- 8, 10, 13 and 13a, comprises a base housing IE5 formed integral with the top housing I enclosing the lower valve 96. Onthis base IE5 is disposed the rotary base member ISB which rotates about a spindle-like extension lili ofthe bushing II. Fitted upon-the rotary base I3@ is a stationary valve disk I3I that is Venclosed within a housing H Aportion i3? xed by bolts |33 to the base |30 which in turn is fastened by bolts i3d to the upper part of support I25. Air is admitted under pressure to the upper face of valve member I3I through a, pipe |36 which connects with pipe 94. The pipe ISG, in this arrangement is coaxial of the valve, and is held against rotation by. its connection with pipe 94.

The valve base I3 has ports lill), equally spaced and leading radially thereinto. The pipes 92 for supplying air to the various testing bells, connect with the outer ends of these ports and the inner ends of the ports open inwardly through the face of the member i?i in equal spacing and in circular arrangement about the central axis of the valve; the upper ends of the ports being designated by Hita in Fig. 13. There are exhaust ports iil opening directly through the valve member i3d in radial alinementwith the ports illa and arranged concentrically about the axis of rotation in a circle that lies within the circle of ports Mita. lThe lower ends of the ports IliI are designed to register with ports M2 leading to atmosphere through the support |25 as seen in Fig. 8, when the valve isV at rest.

The upper valve member I 3! is held against rotation by a keyed connection with the upper end extension im' of the bushing II@ andV it fits against the flat upper face of part in'an air tight joint. The member I 3l has i'lVe ports I 44 `irectly therethrough at an angular spacing of sixty degrees and adapted to register with the corresponding ports llilia at periods of rest of the Valve, however, at the sixth station corresponding to the operators station there ,is no port lii but there is a recess or pocket it in the under surface of thepart I3I adapted to provide a connection between the paired ports Ila and I 4I,

when they areY moving to this station, thereby to exhaust air from the sealed can in the bell corresponding thereto prior to raising of the bell under control of valve 96. Thus, assuming that a can is sealed in a bell, as seenr in Fig. 9, air will` be admitted under pressure tothe can when the corresponding port Ill in valve base I3I), rotating clockwise with respect to its showing in Fig. 13,

passes into registration beneath that port of the member ESI designated as Ilma' in Fig. 13a. This pressure is maintained while the table advances through five successive stations by reason of the fact that atfthe end of each advance movement the port lrl again registers with a port |44. When the table leavesthe testing station, the pocket U56 in the valve member I3I provides a Vconnection between the ports |40 and |744 and thus the air in the can is exhausted to atmosphere while additional air is cut oir, during the time the cylinder is raised at the operators station;

With reference to the location of parts, as seen in Fig. 4, air is applied interiorly of the cans as the bells reach the station on radial line B and continues until they reach station D.

If a can under test has any defect Which will permit of a leak, air pressure applied interiorly thereto will leak to the outside of the can and consequently build up a pressure in the Vsealed space between the can and chamber walls. In order that any pressure thus built up may be visibly indicated, I have provided means for making an air connection between this sealed space and a liquid containing vessel M8 to indicate, by a bubble test, the fact that there is a leak. This connection is automatically made by a valve mechanism, incident to rotation of the machine and the connection takes place when each bell containing the can to be tested reaches the testing station designated at D, in Fig. 3.

By reference to Figs. l and 9, it will be observed that pipes l5@ lead from the various can stations of the table l to a valve ring 52 tted revolubly about the bearing 3 upon a stationary valve base E53.V The outer ends of the pipes |55 communicate with ports 55d drilled through base plates inset in base l, on which the cans are placed for testing and the inner ends of these pipes are threaded into radial ports 55 in the valve ring 52. These ports 55, as seen in Fig. l5, open downwardly from the member |52 in equal spacing and in a circle concentric of the of rotation, and are adapted, on rotation of the ring 52, to successively be brought into registration with an exhaust port |60, alined with the station D, and from which port a pipe ll leads into the open testing vessel Hi8. The pipe enters the base of the vessel and thus when a port its stops in registration with port lll, any air pressure in the chamber surrounding the can, will be exhausted through pipe itl and the presence of a leak in the can will be indicated by the discharge or" air bubbles into the liquid in the testing vessel.

In order that the slight inflation of each can that occurs when the can receives the testing air pressure will not operate to build up a pressure in the chamber surrounding the can, I have provided an arcuate slot 555 in the valve disk E53 and this extends concentric of the valve through an arc from slightly beyond the testing station to the rst station beyond the op-erators position. This slot communicates with an exhaust port iet. Thus, the chamber surrounding the can is open to atmosphere until after the can has received the testing air.

The present machine may readily be applied to the testing of cans of diierent size and shape by a change of testing bells, and adjustment of parts that is'provided for. Also, square, or oblong cans may be accommodated the same as cylindrical cans. Y

Having thus described my invention, what I claim as new therein and desire to secure by Letters Patent is:

l. In a can testing machine, a rotary base provided with stations at which openfend cans may be mounted in upright position for testing, testing bells associated with the base and having open lower ends for receiving the cans, means operable incident to rotary advancement of the base to effect the movement of the bells to enclose.

meansin'the `bells for sealing the open ends of the'cansincident to sealing'of the bells, 'means timedw'ithft'he sealingfof the cans toadmittesting air under pressure thereinto, an air leak indie' cator, a' valve mechanism-'conduits connecting the bells with the valve mechanism and a conduit connecting the valve mechanism `and indicator; said valve mechanism comprising a part rotatwith the base and operable during the inflation period of each can to open its enclosing bell to atmosphere then to close the bell for a definite the-cans and'intosealing .contact with the'base,

period and subsequently to connect the bell withV the leak indicator.

2. In a can testing machine, a rotatably mounted base with stations at denite intervals for the support of open end cans in upright positions for testing, air cylinders supported'abovethe baseto Y' rotate therewitha piston for each cylinder vhaving a tubular rod extended fromoppositeends of its cylinder, a testing bell attached to each rod, f v

a source of air under pressure, valve mechanism connected therewith and witheach of the cylinders and operable in timingv with rotationV ofthe base for admitting air to the cylinders to actuate the pistons to move the bells against thev base thereby to enclose and seal the cans thereon dur-Y ing a predetermined interval of travel, other valve mechanismV connected with a source of air pressure and withrthe said bells through the tubular' 30 piston rods and operable in timing with the can Y cylindersl supported from the base, a piston and rod for each cylinder, a testing bell attached to each rod, means operable in synchronismwith rotation of the base for applying air to the said cylinders for moving the bells to raised, positions and for lowering them against thebase to enclose and seal cans placed thereon and also to seal the bells against the base about the cans, means op-` erable in timing with the sealing of the cans forV applying testing air thereinto, an air leak indicator and a valve mechanism therefor comprising a stationarypart having-aport opening'to'at.- mosphere and a port connected kwith said indicator, and a member rotating with the base and having ports connectedV respectively with the bells when sealed about the cans and adapted to communicate with the `port to atmosphere during inilation oi' thecan and to connect with the port to the indicator at a later periodiin the advancement of the base. j

4. A can testing machine comprising a support, a base rotatably mounted thereon, and equipped with stations at intervals for the support of cans for testing, means for effecting intermittent ad Vance movements of the base to move the rcans by a plurality of advance movements from the loading to the testing station, a standard on the p aised position, as theyy advance'from the testing station to the loading station, and 'foriowering 2,036,116 Y Y Y msm :wherebythesaled bells are connected t .atmosphere during the inationv period of the can sealed therein, andare then'closedduring'advancement'to the'testing station-andare then opened tothe air leak indicator. f n f y WILFQRD E. BURNS; 

